Western Cape Education Department
Directorate: Curriculum FET
LIFE SCIENCES
REVISION BOOKLET
2025 TERM 1
Grade 10
This revision program is designed to assist you in revising the critical
content and skills that you have covered during the 1st term. The
purpose is to prepare you to understand the key concepts and to
provide you with an opportunity to establish the required standard and
the application of the knowledge necessary to succeed in the
examination.
The revision program covers the following topics:
• Scientific skills
• The chemistry of life
• Cells: The basic unit of life
• Cell division: Mitosis
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Life Sciences revision booklet 2025
Grade 10 Term 1
Table of Contents
1.
EXAMINATION WRITING TIPS: ........................................................................................................... 3
1.1
GENERAL TIPS FOR WRITING A TEST OR EXAMINATION IN LIFE SCIENCES: .................................. 3
1.2
HOW TO APPROACH YOUR LIFE SCIENCES TEST OR EXAMINATION: ............................................ 3
TERM 1 CONTENT ...................................................................................................................................... 4
1.
SCIENTIFIC SKILLS: .............................................................................................................................. 4
2.
THE CHEMISTRY OF LIFE..................................................................................................................... 8
3.
CELLS: THE BASIC UNIT OF LIFE ........................................................................................................ 16
4.
CELL DIVISION (MITOSIS) ................................................................................................................. 22
5.
REVISION QUESTIONS: ..................................................................................................................... 24
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Life Sciences revision booklet 2025
Grade 10 Term 1
1.
EXAMINATION/TEST WRITING TIPS:
1.1
GENERAL TIPS FOR WRITING A TEST OR EXAMINATION IN LIFE SCIENCES:
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•
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•
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•
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•
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1.2
Answer ALL the questions in the test or examination.
Number the answers correctly according to the numbering system used in
the question paper.
Present your answers according to the instructions of each question.
Do ALL drawings in pencil and label them in blue or black ink.
Draw diagrams, tables or flow charts only when asked to do so.
The diagrams in question papers are NOT necessarily drawn to scale.
Do NOT use graph paper when drawing graphs.
You must use a non-programmable calculator, protractor and a compass,
where necessary.
Write neatly and legibly.
Make sure that you have all the necessary stationery for your examination
e.g. blue or black pens, a pencil, an eraser, a ruler, a non-programmable
calculator, protractor and a compass.
HOW TO APPROACH YOUR LIFE SCIENCES TEST OR EXAMINATION:
•
Each Life Sciences test or examination question paper consists of TWO
sections i.e. SECTION A and SECTION B
•
When answering a multiple-choice question in Section A, read the question
and four options carefully, evaluate each option and eliminate each
incorrect option.
•
In questions that require only a LETTER you only need to write down a LETTER
e.g. ‘Give the LETTER of the blood vessel that carries oxygenated blood to all
parts of the body’. Other questions might require you to write down both the
LETTER and a NAME e.g. ‘Give the LETTER and NAME of the blood vessel that
carries oxygenated blood to all parts of the body’
•
Use the correct spelling when you use biological terminology in your answers.
•
Use scientific names in terminology and avoid using common names.
•
The instruction verbs e.g. name, give, describe, explain etc. and the mark
allocation per question give an indication of what and how much
information you should provide in your answer.
Table: Instruction verbs and meaning
Instructional
verb
Name
Differentiate
Tabulate
Describe
Explain
Meaning
Give the name of something
Use differences to qualify between two or more categories
Draw a table and indicate the answers as direct pairs.
State in sentences the main points of a process
Give your answer in a cause-effect or statement and reason
sequence
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Life Sciences revision booklet 2025
Grade 10 Term 1
TERM 1 CONTENT
1.
SCIENTIFIC SKILLS:
1.1
Calculations
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•
1.2
You will be expected to do simple calculations that involve addition,
subtraction, multiplication and division.
You must have a calculator.
Show your working of your calculation step by step because marks are
allocated for the steps as well as for the correct answer.
Include the unit in your final answer.
Presentation of data
Scientific data can be presented in various ways e.g. in the form of a table or a
graph.
1.3
Tables
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•
Tables are used to record the results of an investigation
A table must have an appropriate heading
A table is divided into rows and columns
Each column and row may have its own heading with units if applicable.
Rows run from left to right across the table.
Columns are the vertical blocks of a table.
The independent variable is normally in the left-hand column
The dependent variable is normally in the right-hand column
Number of children born with sickle cell disease in some regions in a particular year
REGION
Democratic Republic of Congo
USA
Nigeria
1.4
NUMBER OF CHILDREN BORN WITH SICKLE
CELL DISEASE
39 746
90 128
91 011
Drawing graphs
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Make sure that you know the difference between a line graph, bar graph,
histogram and a pie chart.
Always provide a heading for your graph that includes both independent and
dependent variables.
Label the X and Y-axis which may include the units of measurement like oC,
seconds, years, number of organisms, etc.
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Life Sciences revision booklet 2025
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Grade 10 Term 1
Work out an appropriate scale for the axes.
When drawing a bar graph, remember that the bars should be of equal width.
The spaces between the bars should also be the same.
When drawing a pie chart, you must use a compass to draw the circle of the
chart and a protractor to measure the angles in degrees of the different sectors.
Types of graphs
•
Line graphs show the relationship between two types of information where the
independent variable is continuous. Line graphs are useful in showing trends
over time and are often used for biological data.
•
Bar graphs show different categories of data and are used when the
independent variable is not a set of continuous numbers or continuous groups
(discontinuous data). They are best used to compare values across categories.
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Life Sciences revision booklet 2025
1.5
Grade 10 Term 1
•
Histograms have connected bars displaying continuous data. They are used
when the values of the independent variables are continuous but fit into
categories or groups that follow on after each other.
•
Pie charts are circular charts used to compare parts of the whole. They are
divided into sectors that are equal in size to the quantity represented. They are
used for discontinuous data.
Scientific investigations
Questions on scientific investigations will always be text and data-rich. Read the stem
and investigative process carefully. The list below shows some terms and their
meanings associated with scientific investigations.
Term
Observation
Meaning
What the scientists saw, heard or encountered that
encouraged them to investigate further.
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Grade 10 Term 1
Hypothesis
A possible prediction and/or explanation of the
relationship between the two variables.
Aim
Usually starts with the words ‘to investigate …’ and includes
both variables. It describes what the investigation is trying
to find out.
The independent
(manipulated) variable
This is the variable that the scientists will
manipulate/control. The independent variable appears on
the X-axis of a graph.
The dependent
(responding) variable
This variable is what reacts or responds to the independent
variable. This variable appears on the Y-axis of a graph
The controlled
variables
All other variables that must be kept constant to ensure the
validity of the investigation so that any effect is ONLY due
to the change in the independent variable.
The control
A second set up in the investigation that allows a
comparison with the results of the experiment. The control
is identical to the experiment except that it excludes the
variable that is being tested.
Accuracy
Refers to the care taken when making measurements.
Validity
This refers to the experimental method and how
appropriate it is in addressing the aim of the investigation.
For example, keeping all other factors constant/identifying
the controlled variables helps in making an investigation
valid.
Results
The evidence produced during the investigation that will
either support or refute the hypothesis. These may be
presented in the form of an extract, a table, a
graph or a diagram.
Improving the
reliability of results
Results can be made more reliable if:
• The investigation is repeated
• A bigger sample size is used
• The samples are taken randomly
• Many readings are taken to obtain an average reading
(These depend on the nature of the investigation),
Conclusion
This is directly linked to the aim of the investigation and
confirms or refutes the hypothesis
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Grade 10 Term 1
Formulating a hypothesis:
A hypothesis must:
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•
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have two variables (dependent and independent variables).
state the relationship between the two variables.
be testable; and
state the independent variable first (cause) and then the dependent variable
(effect).
Study the following example of a hypothesis question:
A scientist conducted an investigation to determine the effect of sulphur dioxide on
the growth of young roots of bean seeds.
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He took three gas jars and placed a germinating bean seed in each jar.
A different number of sulphur dioxide bubbles were passed through each jar.
Each jar was sealed with a cover glass.
The increase in length of each young root was measured after 5 days.
Formulate a hypothesis for the above investigation.
If germinating bean seeds are exposed to sulphur dioxide the growth of the roots of
beans will slow down ✓✓
OR
If germinating bean seeds are exposed to sulphur dioxide the growth of the roots of
beans will increase✓✓
OR
If germinating bean seeds are exposed to sulphur dioxide there will be no growth of
the roots of beans✓✓
2.
THE CHEMISTRY OF LIFE
Organic molecules are made up of carbon (C), Hydrogen (H) and oxygen (O) and
some contain other elements, such as nitrogen (N) and phosphorous (P). Cells are
made up of proteins, carbohydrates, lipids, nucleic acids and vitamins.
Inorganic compounds:
•
Inorganic compounds do not contain the element carbon and are not
produced by living organisms e.g. water, gases and minerals.
Water:
•
•
•
Water is the most important inorganic compound that is essential for life.
Water molecules consist of one oxygen (1 O) bonded to two hydrogen
molecules (2 H).
The formula for water is H2O
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Minerals:
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Minerals can be divided into two groups i.e. macro elements and micro
elements.
Macro elements are nutrients that are needed in large quantities
Micro elements are nutrients that are needed in small quantities.
Element
Sodium (Na)
Macro elements
Function
• Important for maintaining of
water balance in the body
• Required for functioning of
nerves and muscles
Potassium(K)
• Required for functioning of
nerves and muscles
• Needed to activate plant
enzymes
Calcium (Ca)
• Required for formation of
bones and teeth in animals
• Functions in blood clotting
• Plays a role in the
permeability of cell
membranes
Phosphorus(P)
• Required for formation of
bones and teeth in animals
Deficiency disease
• Muscular cramps in
humans
• Poor heart and
muscle function in
animals
• Chlorosis (leaves
become yellow
because of a
shortage of
chlorophyll) in
plants
• Rickets in humans
• Poor root growth in
plants
• Rickets in humans
• Stunted growth in
plants
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Life Sciences revision booklet 2025
Grade 10 Term 1
• Component of cell
membranes and nucleic
acids
Element
Iron (Fe)
Iodine(I)
Micro elements
Function
• Required in synthesis of
haemoglobin
• Helps to form chlorophyll in
plants
• Component of the hormone
thyroxin which is secreted by
the thyroid gland in humans
Deficiency disease
• Anaemia in
humans
• Chlorosis in plants
• Goitre (swelling of
neck or larynx) in
humans
Organic compounds
Carbohydrates:
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Carbohydrates are made up of the elements carbon (C), hydrogen (H) and
oxygen (O).
The ratio of H atoms to O atoms is 2:1
Carbohydrates are made up of smaller units called, saccharides
Carbohydrates are divided into three groups according to the number of
saccharides they contain:
➢ Monosaccharides (single sugars) e.g. glucose, fructose and galactose
➢ Disaccharides (double sugars) e.g. maltose, sucrose and lactose.
Disaccharides are formed when two monosaccharides are joined e.g.
Glucose + Fructose
Sucrose + water
➢ Polysaccharides (many sugars) e.g. starch, glycogen and cellulose.
Polysaccharides are long chains of monosaccharides.
Test for carbohydrates:
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Test for glucose: Benedict solution (a blue liquid) is used to test for glucose.
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Life Sciences revision booklet 2025
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Grade 10 Term 1
Prepare a water bath and heat the water.
Pour 5cm3 of Benedict’s solution in a test tube
Add a few drops of the test solution e.g. fruit juice to the Benedict’s solution
Place the test tube into the water bath and observe the colour change after a
few minutes
An orange-red colour change in the test tube indicates a high concentration
of glucose present.
•
Test for starch: Iodine solution (a brown liquid) is used to test for starch
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Place a potato or piece of bread in a dish.
Place a few drops of iodine solution on the peeled potato.
The potato turns blue-black in the presence of iodine solution.
Lipids (fats and oils):
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Lipids contain carbon (C), hydrogen (H) and oxygen (O).
The ratio of H to O is greater than 2:1
One lipid molecule consists of one glycerol molecule and three fatty acid
molecules.
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Life Sciences revision booklet 2025
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Grade 10 Term 1
Saturated fats – have single bonds in the fatty acid chain and are mainly
derived from animals. Saturated fats are mainly solids at room temperature e.g.
butter and cheese.
Unsaturated fats – have one or more double bonds in the fatty acid chain and
are mainly derived from plants. Unsaturated fats are liquids at room
temperature e.g. olive oil, canola oil and sunflower oil.
Cholesterol and heart disease:
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•
•
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Cholesterol is a lipid and a white, wax-like substance that is found in the human
body and is part of cell membranes.
Excessive intake of saturated fats leads to high cholesterol levels in the blood.
High cholesterol levels on the blood cause fatty deposits in arteries thereby
narrowing the arteries
This interferes with the transport of blood and can lead to a heart attack.
Test for fats:
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Grind the test material (e.g., peanuts)
Place a small amount of the test material in a test tube and add about 5cm3 of
ether or ethanol.
Shake the test tube and let it stand for a few minutes.
Filter the test solution and place a few drops of the filtrate (liquid that filtered
through) on a clean filter paper
The ether or ethanol will evaporate, and a translucent fatty stain will form on
the filter paper
Proteins:
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Proteins are large molecules (polymers) and are made up of the elements
carbon(C), hydrogen(H), oxygen(O) and nitrogen(N). Some proteins also
contain phosphorous (P), sulphur (S) and iron (Fe).
Proteins are made up of long chains of amino acids which are the building
blocks (monomers) of proteins.
There are about 20 different amino acids.
The sequence and type of amino acids determine the type of protein.
The bond that form between two amino acids is known as a peptide bond.
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Life Sciences revision booklet 2025
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Grade 10 Term 1
A dipeptide is formed when two amino acids combine, and a tripeptide is
formed when three amino acids combine. A polypeptide is a long chain of
amino acids linked by peptide bonds.
A protein consists of a chain of at least 50 and more amino acids.
Proteins are sensitive to temperature and pH and will denature (protein loses its
shape and can no longer perform its function) at high temperatures and
extreme pH levels.
Test for proteins:
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Test for proteins: The Biuret test is used to test for proteins.
Grind the test material (beans) and add a little water.
Boil the test material until it forms a thin soup
Pour about 5 cm3 of the soup into a test tube and add a few drops of dilute
copper sulphate solution to the test tube.
Add 5 cm3 of sodium hydroxide solution to the mixture
Shake the test tube and heat the mixture
A violet (purple) colour indicates the presence of proteins
Enzymes
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Enzymes are proteins.
Enzymes are biological catalysts that speed up the rate of a chemical reaction
without being used up in the chemical reaction itself.
Chemical reactions that take place in living cells are known as metabolic
reactions.
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Life Sciences revision booklet 2025
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Grade 10 Term 1
Enzymes may be involved in two types of metabolic reactions i.e. anabolic and
catabolic reactions.
During an anabolic reaction a complex molecule is built up from simple
molecules.
During a catabolic reaction a complex reaction is broken down into simple
molecules.
During the digestion of food, complex molecules are broken down into smaller
molecules. These reactions cannot take place without the help of enzymes.
Lock-and-key model of enzyme action:
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The substance on which an enzyme acts is known as the substrate.
The substance that is formed during the reaction is the product.
Enzymes are substrate-specific i.e. a specific enzyme can only act on a specific
substrate e.g. the enzyme sucrase will only react with sucrose etc.
The substrate fits into the enzyme’s active site as a key fit into a lock and an
enzyme-substrate complex is formed.
The reaction takes place and the substrate becomes the product which leaves
the enzyme.
The enzyme is now free to react with other substrate molecules.
Effect of temperature on enzyme activity:
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Enzymes are sensitive to changes in temperature.
Most enzymes are inactive at low temperatures
The temperature at which enzymes work the best is known as their optimum
temperature e.g. 35 ºC - 40 ºC.
An enzyme loses its shape and function and denatures at temperatures above
the optimum temperature.
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Grade 10 Term 1
Effect of pH on enzyme activity:
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Enzymes are sensitive to changes in pH.
Every enzyme has a pH range within which it can function. This is known as the
optimum pH.
Enzymes denature at extreme pH levels.
Enzymes in everyday life:
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•
Biological washing powders contain enzymes e.g. lipase and protease that can
break down stains.
The enzyme protease breaks proteins down into smaller soluble molecules that
can be removed by cleaning agents in the washing powder.
Nucleic acids:
•
•
•
•
Nucleic acids are made up of the elements carbon (C), hydrogen (H), oxygen
(O), nitrogen (N) and phosphorous (P).
There are two types of nucleic acids i.e. DNA (deoxyribonucleic acid) and RNA
(ribonucleic acid)
DNA is found in the nucleus of a cell and it carries the hereditary
characteristics.
RNA is found in the nucleus and cytoplasm of a cell and plays a role in protein
synthesis.
Vitamins:
•
•
Vitamins are organic compounds and are required in small quantities by
animals.
Vitamins are essential for normal metabolism, growth and development of the
human body.
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Life Sciences revision booklet 2025
Vitamin
A
B1
C
D
E
3.
Source
Yellow vegetables,
liver
Brown rice,
wholegrain bread,
legumes
Citrus fruit, tomatoes
Oily fish, milk
Spinach, lettuce
Grade 10 Term 1
Deficiency disease
Night-blindness
Beri-beri
Scurvy
Rickets
Poor nerve conduction, anemia
CELLS: THE BASIC UNIT OF LIFE
Cell structure and function: roles of the organelles
3.1
Cell wall
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•
•
The cell wall is a rigid, non-living layer that is found outside the cell membrane
and surrounds the cell.
The primary cell wall occurs on the outside of the cell membrane and consists
of cellulose.
A cell wall only occurs in plant cells.
Functions of the cell wall
•
•
•
3.2
The cell wall is a support structure that protects the living contents of the plant
cell.
It also gives rigidity to the plant cell.
The cell wall is completely permeable to water and mineral salts.
Cell membrane
•
The cell membrane forms the outer living boundary of the cytoplasm.
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Life Sciences revision booklet 2025
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Grade 10 Term 1
All plant and animal cells have cell membranes
According to the fluid mosaic model the cell membrane consists of a double
layer of phospholipid molecules with large protein molecules embedded in the
layer of phospholipids.
Function of the cell membrane
•
The cell membrane is selectively/differentially permeable and controls the
movement of substances into and out of the cell.
Movement of substances e.g. water, gases and salts into and out of a cell.
Diffusion: The spontaneous movement of molecules of a liquid or gas from an
area of high concentration to an area of low concentration. Diffusion is a
passive process, and no energy is required for this type of transport.
Osmosis: The movement of water molecules from an area of high water
potential to an area of low water potential through a selectively permeable
membrane. Pure water has the highest water potential. Osmosis is a passive
process and does not require energy. Plant cells use osmosis to absorb water
from the soil and transport it to the leaves.
Active transport: The movement of molecules from a low to a high
concentration (against the concentration gradient) through membranes.
Energy is needed for this type of transport.
3.3
Nucleus
•
•
The nucleus consists of a double nuclear membrane with pores, the
nucleoplasm, the nucleolus and tangled threads known as the chromatin
network.
The chromatin network shortens and thickens to form chromosomes when a
cell divides.
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Grade 10 Term 1
Functions of the nucleus
•
•
3.4
The nucleus controls the activities of the cell.
The chromosomes carry hereditary characteristics
Cytoplasm
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•
•
Some of the cytoplasm is in a liquid form and some is in a jelly-like state.
It contains dissolved nutrients and waste products.
In eukaryotic cells, all the organelles are contained within the cytoplasm
except the nucleolus which is contained within the nucleus.
Functions of the cytoplasm
•
•
3.5
The cytoplasm stores substances.
Substances circulate through the movement of the cytoplasm.
Mitochondria
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•
•
•
•
Mitochondria occur in plant and animal cells and are found in the cytoplasm.
It is cylindrically shaped and is enclosed by a double membrane.
The inner membrane contains folds known as cristae.
The cristae increase the inner surface area of the mitochondrion where
chemical reactions take place.
The mitochondrion is filled with a semi-fluid substance, the matrix.
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Grade 10 Term 1
Function of the mitochondrion
•
3.6
The mitochondrion releases energy during cellular respiration.
Ribosomes
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•
•
Ribosomes are small round structures that occur in plant and animal cells.
Ribosomes may occur singly in the cytoplasm or in groups or may be attached
to the endoplasmic reticulum thus forming the rough endoplasmic reticulum.
It consists of RNA and proteins.
Function of the ribosomes
•
3.7
Ribosomes are the sites of protein synthesis.
Endoplasmic reticulum (ER)
•
•
The ER is a membranous network found in plant and animal cells.
There are two types of ER i.e. Rough ER (has ribosomes on its surface) and
Smooth ER (has no ribosomes on its surface)
Function of the ER
•
3.8
The ER transports substances from one part of the cytoplasm to another.
Golgi body
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•
•
The Golgi body consists of a stack of flat membrane-bound sacs called
cisternae.
It is found near the nucleus and endoplasmic reticulum.
It occurs in plant and animal cells.
Functions of the Golgi body
•
•
3.9
The Golgi body plays a role in producing and processing secretions e.g. mucus
and saliva.
It prepares proteins for transport to other parts of the cell.
Plastids
•
•
Plastids only occur in plant cells.
There are 3 types of plastids i.e. chloroplasts, chromoplasts and leucoplasts
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Grade 10 Term 1
Chloroplasts:
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•
•
•
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Chloroplasts are mainly found in the photosynthesizing parts of a plant e.g. the
leaves.
A chloroplast is surrounded by a double membrane.
A fluid matrix, the stroma, fills the chloroplast.
In the stroma are disc-shaped membranes, the lamellae or thylakoids
The lamellae form small stacks, the grana.
The chlorophyll (green pigment) is embedded in the lamellae.
Chromoplasts:
•
•
Chromoplasts occur in yellow, orange and red flowers, leaves and fruit.
They contain pigments called carotenoids.
Leucoplasts:
•
Leucoplasts are colourless plastids that occur mainly in cells that store food e.g.
in potatoes.
Functions of the plastids
•
•
•
3.10
•
•
•
The process of photosynthesis occurs in the chloroplasts
Chromoplasts give the yellow, orange and red colour to flowers, leaves and
fruit
Leucoplasts store food.
Vacuoles
Vacuoles are fluid-filled organelles that occur in the cytoplasm of most plant
cells but are very small or completely absent in animal cells.
A vacuole is enclosed by a selectively permeable membrane called the
tonoplast.
Vacuoles are filled with a liquid called cell sap consisting of water, mineral salts,
sugars and amino acids.
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Grade 10 Term 1
Functions of vacuoles
•
•
•
The vacuole plays an important role in digestion and excretion of cellular waste
and storage of water and organic and inorganic substances.
The vacuole takes in and releases water by osmosis in response to changes in
the cytoplasm, as well as in the environment around the cell.
The vacuole is also responsible for maintaining the shape of plant cells. When
the cell is full of water, the vacuole exerts pressure outwards, pushing the cell
membrane against the cell wall. This pressure is called turgor pressure.
Other types of vacuoles:
•
•
Vesicles - small, spherical sacs which facilitate the metabolism, transport and
storage of molecules.
Lysosomes - small vesicles, mainly found in animal cells, that are filled with
digestive enzymes. These powerful enzymes can digest cell structures and food
molecules such as carbohydrates and proteins.
Differences between plant and animal cells:
Plant Cells
Cell wall present
Plastids present
Large vacuole present
Animal Cells
Cell wall absent
Plastids absent
Vacuole small or absent
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4.
Grade 10 Term 1
CELL DIVISION (MITOSIS)
The period during which a cell grows, replicates genetic material and divides is
known as the cell cycle.
Interphase is the period between two consecutive cell divisions. Cell growth
and DNA replication take place during this phase. After replication has taken
place, the chromosome now consists of two chromatids (double-stranded)
joined by a centromere.
Prophase
• Chromatin network
shortens and thickens to
form individual
chromosomes
• Each chromosome
consists of two chromatids
joined by a centromere
• Nuclear membrane and
nucleolus disappear
• Centrioles separate and
move to opposite poles of
the cell
• Spindle fibre forms
between the centrioles
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Grade 10 Term 1
Metaphase
• Chromosomes move to
the equator and arrange
themselves in a single row
on the equator
• Each chromosome is
attached to the spindle
fibres by its centromere
Anaphase
• The centromere of each
chromosome divides into
two
• The two chromatids
separate
• The spindle fibre contracts
and pulls the chromatids
to opposite poles
• The two chromatids move
to opposite poles
Telophase
• The chromatids now
called chromosomes
arrange themselves at the
poles
• The spindle fibres
disappear
• The nuclear membrane
forms around each group
of chromosomes at each
pole and a nucleolus
forms.
• The cytoplasm divides
(cytokinesis)
• Two identical cells with the
same chromosome
number as the original cell
are formed
The role of mitosis
•
•
•
•
Development and growth - The number of cells increase by mitosis enabling
organisms to grow from a single cell to a complex multicellular organism.
Reproduction - Some organisms use mitosis to produce genetically identical
offspring.
Cell replacement - Cells are constantly replaced by new ones in the body, for
example in the skin.
Replacement of damaged tissues - some organisms use mitosis to replace
body parts.
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Life Sciences revision booklet 2025
5.
Grade 10 Term 1
REVISION QUESTIONS:
•
•
5.1
Work through and answer the questions below.
Please note that HIGHER ORDER questions are in BOLD and marked with a (*)
The table below shows an analysis of the nutrients found in a 100gram portion
of breakfast. The breakfast consists of eggs, bread and butter.
NUTRIENTS IN A 100g
PORTION
Carbohydrates (g)
Fats (g)
Protein (g)
Calcium (mg)
Iron (mg)
Vitamin A (mg)
Vitamin C (mg)
Vitamin B1 (mg)
Eggs
0,0
12,5
11,8
56,0
2,8
675,0
0,0
0,7
FOOD TYPES
Bread
20,2
0,2
2,5
3,3
0,6
12,0
57,0
0,2
Butter
0,1
85,2
0,0
13,8
0,15
2344,0
0,20
0,0
5.1.1
Name ONE nutrient that is essential for the manufacturing of enzymes.
(1)
5.1.2
Identify the food type that would be best for a person who suffers from nightblindness. Give a reason for your answer.
(2)
*5.1.3 Calculate the amount of iron found in a 500g serving of the above breakfast.
Show ALL your workings
(3)
5.1.4
Which vitamin will prevent Beri-Beri?
(1)
*5.1.5 Explain why an athlete should include bread in his/her breakfast.
5.2
5.2.1
5.2.2
(2)
The diagrams below show different organic compounds.
Name the organic compound represented by diagrams A and C
respectively.
(2)
Identify the type of bond labeled X.
(1)
25
Life Sciences revision booklet 2025
5.3
Grade 10 Term 1
An investigation was carried out to study the effect of temperature on the
action of pepsin, a protein-digesting enzyme present in the stomach fluid.
The investigation was set up as follows:
•
•
•
•
10 grams of protein was placed in each of five test tubes.
20 ml of stomach fluid was added to each of the five test-tubes.
Test-tubes were then taken and kept at different temperatures.
After 24 hours, the contents of each test-tube were tested to determine the
amount of protein that had been digested.
The results are shown in the table below.
Test tubes
Temperature (ºC)
1
2
3
4
5
5
10
20
35
70
Amount of protein
digested (g)
1
2
4
9
0
*5.3.1 State the:
(a) Independent variable
(1)
(b) Dependent variable
(1)
*5.3.2 State ONE way in which the reliability of this investigation could be
improved.
(1)
*5.3.3 Draw a line graph to show the results of this investigation.
(6)
*5.3.4 Give a possible reason why no proteins were digested at 70°C
(1)
26
Life Sciences revision booklet 2025
Grade 10 Term 1
5.4
The following diagrams represent two cells.
5.4.1
Which one of these diagrams (X or Y) represents a plant cell?
(1)
5.4.2
List THREE visible reasons for your answer in QUESTION 5.4.1
(3)
5.4.3
What is the function of C in cell X?
(1)
5.4.4
Name the process in cell X where B plays a role.
(1)
5.4.5
Write down the LETTER IN CELL Y that can be associated with each of the
following:
(a)
Transport substances in the cytoplasm
(1)
(b)
Turgor pressure
(1)
(c)
Photosynthesis
(1)
5.5
The diagram below represents a mitochondrion found in plant and animal cells.
5.5.1
Identify parts X and Y.
(2)
27
Life Sciences revision booklet 2025
Grade 10 Term 1
*5.5.2 A scale showing 1µm (micrometres) is shown above the organelle. Measure the
organelle between points A and B and use the scale to calculate the length of
the organelle in micrometres. Show ALL your workings.
(3)
5.6
The diagram below is a representation of one of the phases of mitosis.
5.6.1
Identify parts A, B, C and D.
(4)
5.6.2
What phase of mitosis is illustrated in the above diagram?
(1)
*5.6.3 Give TWO visible reasons for your answer in QUESTION 5.6.2.
(2)
*5.6.4 How many chromosomes will be found in each of the cells at the end of
mitosis shown in the diagram.
*5.6.5 Differentiate between telophase of plant cell and animal cell.
5.7
(1)
(2)
Read the extract below.
A common misconception is that cancer is incurable. With early diagnosis
and proper treatment, the chances of survival can be good.
However, once cancer spreads to other parts of the body, it is difficult to
treat and to cure. Nowadays, the treatment used to destroy cancer cells
could be radiation therapy, which is the use of high-energy rays to destroy
cancer cells, or chemotherapy that uses chemicals to destroy cancer cells.
Some side-effects of these treatments may be loss of hair and nausea.
5.7.1
What is cancer?
(2)
*5.7.2 Give TWO reasons why you think that there are more people that suffer from
cancer nowadays compared to 30 years ago.
(2)
5.7.3
Name TWO side-effects of treatment by chemotherapy.
(2)
28
Life Sciences revision booklet 2025
5.8
The root of an onion is a rapidly growing part of the onion. Many cells will be in
different stages of mitosis. A sample of an onion tip was stained and studied
under a microscope.
The various phases of mitosis were identified, and the number of cells counted
in each phase. The results are recorded in the table below.
Phase of mitosis
Interphase
Prophase
Metaphase
Anaphase
Telophase
5.8.1
Grade 10 Term 1
Number of cells
154
30
7
22
12
Which phase produced the:
(a)
Highest number of cells
(1)
(b)
Lowest number of cells
(1)
*5.8.2 Calculate the percentage of cells produced during prophase. Show ALL your
workings.
(3)
5.8.3
Describe the events of anaphase.
(3)
*5.8.4 Assuming a cell takes 24 hours to complete one cycle. Calculate the duration
of the interphase. Show ALL calculations.
(3)
*5.8.5 Draw a bar graph to represent the total number of cells in each phase of the
cell cycle.
(6)
END OF DOCUMENT